Soot, produced from the incomplete combustion of the coal, oil (such as diesel oil), wood or other carbonaceous materials, mainly consists of carbon. The exhaust gas of a diesel engine has a high level of carbonaceous soot, which is undesirable in view of environment protection. One approach for reducing/eliminating the soot emissions of a diesel engine is the employment of a diesel particulate filter in the exhaust gas system of the diesel engine. In order to decrease the temperature for periodically regenerating the diesel particulate filter and perform the regeneration continuously in situ, catalysts may be added to the diesel fuel, or may be impregnated in or coated/deposited onto the wall(s) of the diesel particulate filter to promote the oxidization of soot trapped in the diesel particulate filter at a relatively low oxidization initiation temperature.
U.S. Pat. No. 7,797,931 discloses a catalyst composition for use on a diesel particulate filter for facilitating soot oxidation comprising a catalytic metal comprising a platinum group metal selected from the group consisting of Pt, Pd, Pt—Pd, and combinations thereof and the cost of platinum group metals are high.
US patent application publication No. 2009/0203517 discloses a carbon-based combustion catalyst obtained by burning sodalite or the mixture of sodalite with an alkali metal source and/or an alkaline earth metal source.
Interstitial Cristobalite-type Compounds (Na2O)≦0.33Na[AlSiO4]((Na2O)≦0.66Na2[Al2Si2O8], or Na≦3.32Al2Si2O≦8.66) have been reported in an article titled as Interstitial Cristobalite-type Compounds (Na2O)≦0.33Na[AlSiO4] and published in JOURNAL OF SOLID STATE CHEMISTRY 61, 40-46 (1986). Na8Al4Si4O18 (or (Na2O)Na2[Al2Si2O8], or Na4Al2Si2O9) has been reported in Beitrage zur Beaktionsfahigkeit der silicate bei niedrigen temperaturen, II. Mitteilung., Die Strukturen Na2O-reicher carnegieite., Von Werner Borchert and Jurgen Keidel, Heidelberg, Mit 6 Textabbildungen, (Eingegangen am 17, Marz 1947). US patent application publication No. 2011/0319690 discloses that a carnegieite-like material of formula (Na2O)xNa2[Al2Si2O8], wherein 0<x≦1 may be used for converting carbon into a carbon oxide and hydrocarbon cracking in presence of steam.
It is desirable to develop a new material useful for the regeneration of a diesel particulate filter by way of oxidization of soot and a method for using the new material.